Encapsulated insulating product and method for making same

ABSTRACT

Encapsulated insulation product includes a mattress ( 1 ) of fibres and a cladding covering the two principal surfaces ( 2, 3 ) and the two lateral surfaces ( 4, 5 ) of the mattress, this cladding including a first covering means in the form of a band ( 6 ) which covers at least a central part of the first principal surface ( 2 ) without extending beyond it and whilst being connected thereto, and a second covering means ( 7 - 9 ) which covers the second principal surface ( 3 ) of the mattress, its two lateral surfaces ( 4, 5 ) and marginal parts of its first principal surface, the second covering means being connected to the first and second principal surfaces and floating freely along the opposite lateral surfaces ( 4, 5 ) of the mattress.

The present invention relates to an encapsulated insulation product,comprising a mattress of fibres which extends longitudinally andcomprises first and second opposite principal faces, first and secondopposite lateral faces and first and second opposite end faces, and acladding covering two principal surfaces and two lateral surfaces of themattress, this cladding comprising a first covering means in the form ofa band which covers at least a central part of the first principalsurface of the mattress without extending beyond this first surface andbeing connected thereto, and a second covering means which successivelycovers the second principal surface of the mattress, its two lateralsurfaces and marginal parts of its first principal surface.

Such products which, through their encapsulation, allow manipulationwithout contact with the core of fibres, a contact which may proveinconvenient and even irritating for the operator, have been known for along time. Losses of particles of fibres to the outside, with thepossible formation of dust, may thus be avoided. Moreover, the externalappearance of the product is better finished, even in the coiled stateof the fibre core in mattress form.

The patent U.S. Pat. No. 5,240,527 and the Japanese patent applications51-064584, 52-135383 and 55-164150 can be cited for example. In thesepatent documents, a second covering band is connected solely to thefirst principal surface by means of the first covering band. There is noconnection on the second covering band either with the second principalsurface of the mattress of fibres or with the lateral surfaces. Theseproducts therefore have a recognised mechanical weakness through thefact that they are liable to be delaminated, a respective movementbetween the mattress and the covering bands being difficult to avoid.With a view to attempting to remedy this drawback, it is possible tomake provision, at the time of the encapsulation and bonding, forvigorously pressing each constituent of the product against each other.However, in this case, the mattress of fibres is encapsulated in ahighly compressed state, which reduces its insulation capability.

An encapsulated insulation product of this type is also known in which asecond covering band is also connected to the second principal surfaceand to at least one lateral surface, preferably to the two lateralsurfaces (see WO 97/08401). The problem of the delamination of thecomposite product is thus largely surmounted. However, the encapsulationis such that the air present in the mattress of mineral fibres canscarcely escape when the mattress is coiled after its manufacture. Theresult is a difficulty in coiling the product and, for the same volumeof roll, it is possible to store a less long length of product.

There are also known systems for the mutual fixing of two covering bandsaround a mattress of fibres, for example using tabs folded from thesebands whilst projecting laterally outside the product, so as to be ableto be bonded to each other (see EP-A-0839968 and U.S. Pat. No.2,028,253). The presence of these tabs presents a major drawback in theapplication of rolls alongside each other. Manufacture proves morecomplex and packaging in rolls more complicated.

Insulation products are also known in which the mattress of fibres ispackaged in a perforated film so as to improve the discharge of air fromthe mattress when it is compressed and the return of the mattress to itsinitial shape when the product is applied on the site to be insulated(see U.S. Pat. No. 5,362,539). These perforations obviously have theeffect of weakening the packaging film vis-á-vis mechanical stresses.

The purpose of the present invention is to propose an encapsulatedinsulation product as indicated at the start, which affords at the sametime protection for the operator and the environment, good resistance todelamination and satisfactory suitability for compression, and then anautomatic expansion of the mattress of fibres when the compression forcedisappears. Advantageously, this product must also have a finished andcommercially favourable external appearance and be easy to store andapply.

These problems have been resolved according to the invention by anencapsulated product as indicated at the start in which the secondcovering means is connected to the first and second principal surfacesand floats freely along the opposite lateral surfaces of the mattress.Through the fact that the first covering means in the form of a band isfirmly fixed to the first principal surface of the mattress of fibresand the second covering means is firmly fixed to the second principalsurface and also to the first principal surface, at its marginal parts,the product has irreproachable mechanical resistance to delamination.Moreover, the floating sides of the covering enable air to escape easilyfrom the product during the compression stage, during its winding inrolls, and enables the product to recover its initial thickness when therolls are unwound. All this without having to provide openings in thecovering, nor microperforations, which weaken the latter.

According to one embodiment of the invention, the second covering meansis a band of non-woven material. The covering of the product is thusformed from two covering bands. As a non-woven material appropriate forthe second covering band, polypropylene (PP) or polyester (PES) can forexample be cited.

According to another embodiment of the invention the second coveringmeans consists of a central strip which covers at least a central partof the second principal surface of the mattress and which is connectedthereto, and two lateral strips attached to the central strip on eachside thereof, each lateral strip passing in a floating manner along alateral surface of the mattress, and covering at least a marginal partof the first principal surface of the mattress and at least a marginalpart of the second principal surface whilst being connected to these.

The cladding of the product is thus formed from four different pieces,the first covering band, the central strip and the lateral strips, whichcan thus each be of different natures according to the functionattributed to them and the properties expected of them. This also makesit possible to optimise the mechanical strength of the whole, forexample by determining the width of double covering on the first andsecond principal surfaces of the mattress.

According to one advantageous embodiment of the invention, the centralstrip of the second covering means is a vapour-arresting strip which cancover the whole of the second principal surface of the core. In this wayan insulation product is obtained which is particularly appropriate forthe insulation of dwelling houses, which prevents penetration ofmoisture into the mattress of fibres, and therefore the drawbacksassociated with such penetration.

The vapour arresters used in insulation products according to theinvention are well known to persons skilled in the art. It is possiblefor example to envisage a sheet of paper, advantageously of the krafttype, which is clad with a coextruded polymer film or a plastic film,possibly metallised, or an aluminium film.

The lateral strips are preferably made from a non-woven material,advantageously very flexible to enable them to buckle when the productis compressed. For example, polypropylene (PP) or polyester (PES) can beenvisaged.

The first covering band can be made from a woven or non-woven material.It is possible to envisage for example a non-woven polyester orpolyester/viscose or a glass cloth.

Other embodiments of the product according to the invention areindicated in the accompanying claims.

The present invention also concerns a method of manufacturing anencapsulated insulation product according to the invention.

There is provided, according to the invention, such a method comprisinga depositing of the first covering means in the form of a band on thefirst principal surface of the mattress of fibres and its connectionthereto, an application of the second covering means to the secondprincipal surface of the mattress of fibres and its connection thereto,a folding of the second covering means along the opposite lateralsurface of the mattress and a folding of the second covering means overat least the marginal parts of the first principal surface withconnection of the second covering means thereto, so that it floatsfreely along the opposite lateral surfaces of the mattress.

According to an advantageous embodiment of the method according to theinvention, the second covering means consists of a central strip and twolateral strips and the method also comprises, before or during theapplication of the second covering means to the second principal surfaceof the mattress, an attachment of the lateral strips to the centralstrip, on each side thereof.

The connection of the covering means to the first and second surfaces ofthe mattress and of the covering means between them, as well as theattachment of the lateral strips to the central strip, can be effectedby any means known to specialists. Bonding by means of a suitableadhesive is preferably envisaged.

Other embodiments of the method according to the invention are indicatedin the accompanying claims.

Other details and particularities of the invention will emerge from thedescription given below, non-limitingly, with reference to theaccompanying drawings.

FIGS. 1 and 2 depict a view in transverse section of an insulationproduct according to the invention, in the expanded state andrespectively in the compressed state.

FIGS. 3 to 5 show the steps of three different embodiments of aninsulation product according to the invention, depicted in a partiallybroken form.

In the drawings, the identical or similar elements are designated by thesame references. It should be noted that, in these drawings, theproportions of the elements do not correspond to reality and some valueshave been exaggerated to permit better understanding.

FIG. 1 depicts a view in section of an embodiment of an insulationproduct, thermal or acoustic, according to the invention.

This product, as illustrated, comprises a mattress 1 of glass fibres ormineral fibres which extends longitudinally. In the view in transversesection it can be seen that this mattress has a first principal surface2, a second opposite principal surface 3, a first lateral surface 4 anda second opposite lateral surface 5. The product also has two oppositeend surfaces, not shown in the drawings.

A cladding covers the two principal surfaces 2 and 3 and the two lateralsurfaces 4 and 5.

In the example embodiment illustrated, this cladding comprises acovering strip 6 made from non-woven material, for example polyester,which covers a central part of the first principal surface 2. It doesnot entirely reach the edges thereof, although this can be envisaged.

The cladding also comprises a covering means formed by three strips, anormal vapour-arresting strip 7 which covers at least a central part andpreferably all the second principal surface 3 of the mattress, and twolateral strips 8 and 9 attached to the vapour-arresting strip, on eachside thereof. Each lateral ribbon passes in a floating manner along thelateral surfaces 4 and 5 of the mattress, that is to say it is not fixedto these.

As can be seen in FIGS. 1 and 2, the covering band 6 is, in the exampleembodiment illustrated, connected to the principal surface 2, forexample by a layer of hot-melt binder 21 which affords the adhesion ofthe band 6 to the glass fibre of the mattress 2 and to the foldedlateral edges 10 and 11 of the lateral strips 8 and 9.

The vapour-arrester 7 is, in the example embodiment illustrated, a filmof aluminised plastics material which is connected to the principalsurface 3 and to the lateral edges 12 and 13 of the lateral strips 8 and9, for example by a layer of glue based on polyvinyl acetate 22.

The edges 10 and 12 and respectively 11 and 13 of the lateral strips arethemselves directly connected to the principal surface 2 andrespectively to the principal surface 3 by a hot-melt binder 23 forexample. As a variant, provision can be made not to directly bond theedges 12 and 13 to the principal surface 3, their connection then beingobtained by means of the vapour-arresting strip.

It is obvious that the edges of the lateral strips 4 and 5 can beprovided fixed to the principal surface, not in direct contact with themattress, but also by means of the covering band 6 and/or thevapour-arresting strip 7. These are then interposed between the edges ofthe lateral strips and the mattress.

As can be seen in FIG. 2, when the mattress is in the compressed state,the lateral strips 8 and 9, by buckling, separate from the mattress 1and allow the air contained therein to be released easily.

FIG. 3 illustrates a method of manufacturing an insulation productaccording to the invention in which a vapour arrester is not necessary.

A core 14 of glass fibres is first of all formed, and is next passedthrough a polymerisation oven which will enable the fibres to be bondedto each other by means of a polymerisable binder with which the fibreswere previously treated in a known manner. On emerging, the core 14 iscut along its edges 15 and 16 in order to give, after cutting, amattress 1 having a predetermined and definitive width.

A glue of the hot-melt type is then applied to the entire principalsurface 3 of the mattress and to the longitudinal edges of the principalsurface 2. Then a covering band 7 made from a suitable non-wovenmaterial is applied and glued to the principal surface 3 of themattress.

Using suitable means known to persons skilled in the art, the coveringband 7 is first of all folded along the opposite lateral surfaces 4 and5 of the mattress, and then folded over the previously glued edges ofthe principal surface 2, being thus connected thereto.

In the last step, a covering band 18 made from non-woven materialpreviously coated with an adhesive material, for example of the hot-melttype, is deposited on the principal surface 2 of the mattress whilstcovering this and part of the top folded edges 19 and 20 of the coveringband 17. In a variant, provision can of course be made for the adhesivematerial to be first applied to the glass wall of the mattress, insteadof the covering band.

A firm connection is thus obtained with the two opposite principalsurfaces of the mattress, without connection with the lateral surfaces.The product fabricated has a very advantageous finished appearance. Itcomprises solely two covering bands for encapsulating the mattress offibres and can be compressed and expanded without any problem, withoutrisk of delamination between the constituents.

It should be noted that this fabrication advantageously takes place on aline which moves the mattress continuously. The equipment for gluing,moving, transporting or folding the bands or the mattress, as well asthe polymerisation oven, are devices well known per se to personsskilled in the art.

FIG. 4 illustrates a method of manufacturing an advantageous embodimentof an insulation product according to the invention, in which avapour-arresting strip has been provided.

In this embodiment, the cladding serving for the encapsulation consistsof four pieces: a cladding band 6 made from non-woven material, avapour-arresting strip 7 and two lateral strips 8 and 9 made fromnon-woven material.

In this example embodiment, the cladding band 6 made from non-wovenmaterial, coated with a binder, for example phenolic, is deposited onthe fibre core 14, before it passes into the polymerisation oven. Theband 6 is thus connected to the core 14 during this passage.

After emerging from the oven, the lateral edges of the core 14 are cut,which gives the mattress 1 of defined thickness.

A vapour-arresting strip 7, normal per se, and to which there areattached on each side, for example by adhesive bonding, lateral strips 8and 9 made from non-woven material, is applied to the principal surface3 of the mattress. The vapour-arresting strip is for example aplasticised kraft paper provided on its top face with a foam glue bymeans of which the paper adheres to the principal surface 3 and to thelateral edges 12 and 13 of the lateral strips 8 and 9.

The lateral strips are then folded along the lateral surfaces 4 and 5 ofthe mattress, and then folded over this and the marginal parts of theband 7. On the internal face of the edges of the lateral strips or atthe edges of the principal surface 2 and 3, the presence of an adhesivehas been provided for, for bonding the lateral strips to these surfacesand to the band 7 of non-woven material.

The adhesion of the lateral strips to the principal surfaces or to theband 7 can be obtained by any suitable glue, for example by a polyvinylacetate, foamed or not, by a hot-melt glue or by a reactivatable glue.

As may be remarked, it is possible, by means of this manufacturingmethod, to apply a composite encapsulation in which each constituent hasan optimum composition according to that for which it serves. Inaddition, the corners of the product can be reinforced by means of adouble thickness of material which improves their mechanical strength.Finally, on the production line, the application stations do not allhave to be situated at the same point, which facilitates the operations.A different marking of the constituent parts is also permitted. Forexample, it is possible to introduce a logo on the covering band 7 andlength markings on the lateral strip.

FIG. 5 illustrates a method of manufacturing an embodiment of aninsulation product as depicted in FIGS. 1 and 2.

In this example, the core 14 emerges from the polymerisation oven and isimmediately cut to the required length in order to form the mattress 1.The two lateral strips 8 and 9 are then moved at the same time as thevapour-arresting strip 7. By application to the principal surface 3,they are, by means of an adhesive layer, connected to the previouslyglued vapour-arresting strip 7. The strips are then folded along thelateral surfaces 4 and 5 of the mattress, and then folded against theprincipal surface 2 to which they are connected in the manner alreadydescribed.

On top of this there is then deposited a covering band 6, which is inits turn glued to the principal surface 2 of the mattress and to thefolded edges of the lateral strips.

It must be understood that the present invention is in no way limited tothe embodiments described above and that many modifications can be madethereto without departing from the scope of the accompanying claims.

1. Encapsulated insulation product comprising: a mattress (1) of fibres,which extends longitudinally and comprises first (2) and second (3)opposite principal surfaces, first (4) and second (5) opposite lateralsurfaces, and first and second opposite end faces, and a claddingcovering the two principal surfaces and the two lateral surfaces of themattress, this cladding comprising a first covering means in the form ofa band (6, 18) which covers at least a central part of the firstprincipal surface (2) of the mattress, without extending beyond thisfirst surface and whilst being connected thereto, and a second coveringmeans (7-9; 17) which successively covers the second principal surface(3) of the mattress, its two lateral surfaces (4, 5) and marginal partsof its first principal surface (2), wherein the second covering means(7-9; 17) is connected to the first and second principal surfaces (2, 3)and floats freely along the opposite lateral surfaces (4, 5) of themattress (1).
 2. Insulation product according to claim 1, wherein thesecond covering means is a band of non-woven material (17). 3.Insulation product according to claim 1, wherein the second coveringmeans consists of a central strip (7) which covers at least a centralpart of the second principal surface (3) of the mattress and which isconnected thereto, and two lateral strips (8, 9) attached to the centralstrip (7), on each side thereof, each lateral strip passing in afloating manner along a lateral surface (4, 5) of the mattress, andcovering at least a marginal part of the first principal surface (2) ofthe mattress and at least a marginal part of its second principalsurface (3) whilst being connected to these.
 4. Insulation productaccording to claim 3, wherein the central strip (7) of the secondcovering means is a vapour-arresting strip which can cover the whole ofthe second principal surface (3) of the core.
 5. Insulation productaccording to claim 3, wherein the lateral strips (8, 9) of the secondcovering means are made from a non-woven material.
 6. Insulation productaccording to claim 3, wherein each lateral strip (8, 9) of the secondcovering means is in direct abutment on the second principal surface (3)of the mattress whilst, in this position, being partially covered by thecentral strip (7) of the above-mentioned second covering means. 7.Insulation product according to claim 3, wherein each lateral strip (8,9) of the second covering means is in direct abutment on the firstprincipal surface (2) of the mattress, whilst, in this position,possibly being covered partially by the first covering means in the formof a band (6, 18).
 8. Insulation product according to claim 3, whereineach lateral strip (8, 9) of the second covering means at leastpartially covers the first covering means in the form of a band (6, 18)connected to the first principal surface (2) of the mattress and whereinit is connected to the first covering means in the form of a band (6,18).
 9. Insulation product according to claim 1, wherein the firstcovering means in the form of a band (6, 18) is made from a woven ornon-woven material.
 10. Method of manufacturing an insulation productaccording to claim 1, comprising: depositing the first covering in theform of a band on the first principal surface of the mattress of fibresand its connection thereto, application of the second covering means tothe second principal surface of the mattress of fibres and itsconnection thereto, folding over the second covering means along theopposite lateral surfaces of the mattress, and folding the secondcovering means over at least the marginal parts of the first principalsurface with connection of the second covering means to this, so that itfloats freely along the opposite lateral surfaces of the mattress. 11.Method according to claim 10, wherein the depositing of the firstcovering means in the form of a band takes place before the said foldingof the second covering means, so that the latter, after folding, atleast partially covers the edges of the first covering means in the formof a band, and wherein the method also comprises a connection betweenthe second covering means and the said edges of the first covering meansin the form of a band, so that the said connection of the secondcovering means to the first principal surface takes place by means ofthe first covering means in the form of a band.
 12. Method according toclaim 10, wherein the said folding of the second covering means takesplace before the said depositing of the first covering means in the formof a band so that it is connected to the first principal surface indirect abutment thereon.
 13. Method according to claim 10, wherein thesecond covering means consists of a central strip and two lateral stripsand in that the method also comprises, before or during the applicationof the second covering means to the second principal surface on themattress, an attachment of the lateral strips to the central strip, oneach side thereof.
 14. Method according to claim 10, including apolymerization of a binder by means of which the fibres of the mattressare treated and a cutting of the mattress to size after polymerization.15. Method according to claim 14, wherein for the said polymerization,it comprises a passage of the mattress of fibres through apolymerization oven, after the said depositing of the first coveringmeans in the form of a band, and wherein the connection of the latter tothe first principal surface of the mattress takes place in the oven. 16.Method according to claim 14, wherein the polymerization and the cuttingto size take place before the said depositing of the first coveringmeans in the form of a band and the said application in the secondcovering means.